Diabetic Heart Disease

The term "diabetic heart disease" (DHD) refers to heart disease that develops in people who have diabetes. Compared with people who don't have diabetes, people who have diabetes:

Are at higher risk for heart disease

Have additional causes of heart disease

May develop heart disease at a younger age

May have more severe heart disease

What Is Diabetes?

Diabetes is a disease in which the body's blood glucose (sugar) level is too high. Normally, the body breaks down food into glucose and carries it to cells throughout the body. The cells use a hormone called insulin to turn the glucose into energy.

The two main types of diabetes are type 1 and type 2. In type 1 diabetes, the body doesn't make enough insulin. This causes the body's blood sugar level to rise.

In type 2 diabetes, the body's cells don't use insulin properly (a condition called insulin resistance). At first, the body reacts by making more insulin. Over time, though, the body can't make enough insulin to control its blood sugar level.

For more information about diabetes, go to the National Institute of Diabetes and Digestive and Kidney Diseases' Introduction to Diabetes Web page.

What Heart Diseases Are Involved in Diabetic Heart Disease?

Coronary Heart Disease

In CHD, a waxy substance called plaque (plak) builds up inside the coronary arteries. These arteries supply your heart muscle with oxygen-rich blood.

Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. When plaque builds up in the arteries, the condition is called atherosclerosis (ATH-er-o-skler-O-sis).

Plaque narrows the coronary arteries and reduces blood flow to your heart muscle. The buildup of plaque also makes it more likely that blood clots will form in your arteries. Blood clots can partially or completely block blood flow.

CHD can lead to chest pain or discomfort called angina (an-JI-nuh or AN-juh-nuh), irregular heartbeats called arrhythmias (ah-RITH-me-ahs), a heart attack, or even death.

Heart Failure

Heart failure is a condition in which your heart can't pump enough blood to meet your body's needs. The term “heart failure” doesn't mean that your heart has stopped or is about to stop working. However, heart failure is a serious condition that requires medical care.

If you have heart failure, you may tire easily and have to limit your activities. CHD can lead to heart failure by weakening the heart muscle over time.

Diabetic Cardiomyopathy

Diabetic cardiomyopathy is a disease that damages the structure and function of the heart. This disease can lead to heart failure and arrhythmias, even in people who have diabetes but don't have CHD.

Overview

People who have type 1 or type 2 diabetes can develop DHD. The higher a person's blood sugar level is, the higher his or her risk of DHD.

Diabetes affects heart disease risk in three major ways.

First, diabetes alone is a very serious risk factor for heart disease, just like smoking, high blood pressure, and high blood cholesterol. In fact, people who have type 2 diabetes have the same risk of heart attack and dying from heart disease as people who already have had heart attacks.

Second, when combined with other risk factors, diabetes further raises the risk of heart disease. Although research is ongoing, it's clear that diabetes and other conditions—such as overweight and obesity and metabolic syndrome—interact to cause harmful physical changes to the heart.

Researchers continue to study these processes because all of the details aren't yet known.

Coronary Atherosclerosis

Atherosclerosis is a disease in which plaque builds up inside the arteries. The exact cause of atherosclerosis isn't known. However, studies show that it is a slow, complex disease that may start in childhood. The disease develops faster as you age.

Coronary atherosclerosis may start when certain factors damage the inner layers of the coronary (heart) arteries. These factors include:

High amounts of sugar in the blood due to insulin resistance or diabetes

Plaque may begin to build up where the arteries are damaged. Over time, plaque hardens and narrows the arteries. This reduces the flow of oxygen-rich blood to your heart muscle.

Eventually, an area of plaque can rupture (break open). When this happens, blood cell fragments called platelets (PLATE-lets) stick to the site of the injury. They may clump together to form blood clots.

Blood clots narrow the coronary arteries even more. This limits the flow of oxygen-rich blood to your heart and may worsen angina (chest pain) or cause a heart attack.

Metabolic Syndrome

Metabolic syndrome is the name for a group of risk factors that raises your risk of both CHD and type 2 diabetes.

If you have three or more of the five metabolic risk factors, you have metabolic syndrome. The risk factors are:

A large waistline (a waist measurement of 35 inches or more for women and 40 inches or more for men).

A high triglyceride (tri-GLIH-seh-ride) level (or you’re on medicine to treat high triglycerides). Triglycerides are a type of fat found in the blood.

A low HDL cholesterol level (or you're on medicine to treat low HDL cholesterol). HDL sometimes is called "good" cholesterol. This is because it helps remove cholesterol from your arteries.

High blood pressure (or you’re on medicine to treat high blood pressure).

A high fasting blood sugar level (or you're on medicine to treat high blood sugar).

It's unclear whether these risk factors have a common cause or are mainly related by their combined effects on the heart.

Obesity seems to set the stage for metabolic syndrome. Obesity can cause harmful changes in body fats and how the body uses insulin.

Chronic (ongoing) inflammation also may occur in people who have metabolic syndrome. Inflammation is the body's response to illness or injury. It may raise your risk of CHD and heart attack. Inflammation also may contribute to or worsen metabolic syndrome.

Research is ongoing to learn more about metabolic syndrome and how metabolic risk factors interact.

Insulin Resistance in People Who Have Type 2 Diabetes

Type 2 diabetes usually begins with insulin resistance. Insulin resistance means that the body can't properly use the insulin it makes.

People who have type 2 diabetes and insulin resistance have higher levels of substances in the blood that cause blood clots. Blood clots can block the coronary arteries and cause a heart attack or even death.

The Interaction of Coronary Heart Disease, High Blood Pressure, and Diabetes

Each of these risk factors alone can damage the heart. CHD reduces the flow of oxygen-rich blood to your heart muscle. High blood pressure and diabetes may cause harmful changes in the structure and function of the heart.

Having CHD, high blood pressure, and diabetes is even more harmful to the heart. Together, these conditions can severely damage the heart muscle. As a result, the heart has to work harder than normal. Over time, the heart weakens and isn’t able to pump enough blood to meet the body’s needs. This condition is called heart failure.

As the heart weakens, the body may release proteins and other substances into the blood. These proteins and substances also can harm the heart and worsen heart failure.

Risk Factors

People who have type 1 or type 2 diabetes are at risk for diabetic heart disease (DHD). Diabetes affects heart disease risk in three major ways.

First, diabetes alone is a very serious risk factor for heart disease. Second, when combined with other risk factors, diabetes further raises the risk of heart disease. Third, compared with people who don't have diabetes, people who have the disease are more likely to:

Have heart attacks and other heart and blood vessel diseases. In men, the risk is double; in women, the risk is triple.

Have more complications after a heart attack, such as angina (chest pain or discomfort) and heart failure.

Die from heart disease.

The higher your blood sugar level is, the higher your risk of DHD. (A higher than normal blood sugar level is a risk factor for heart disease even in people who don't have diabetes.)

Type 2 diabetes raises your risk of having “silent” heart disease—that is, heart disease with no signs or symptoms. You can even have a heart attack without feeling symptoms. Diabetes-related nerve damage that blunts heart pain may explain why symptoms aren't noticed.

Other Risk Factors

Other factors also can raise the risk of coronary heart disease (CHD) in people who have diabetes and in those who don't. You can control most of these risk factors, but some you can't.

Risk Factors You Can Control

High blood pressure. Blood pressure is considered high if it stays at or above 140/90 mmHg over time. If you have diabetes or chronic kidney disease, high blood pressure is defined as 130/80 mmHg or higher. (The mmHg is millimeters of mercury—the units used to measure blood pressure.)

Smoking. Smoking can damage and tighten blood vessels, lead to unhealthy cholesterol levels, and raise blood pressure. Smoking also can limit how much oxygen reaches the body's tissues.

Prediabetes. This is a condition in which your blood sugar level is higher than normal, but not as high as it is in diabetes. If you have prediabetes and don't take steps to manage it, you'll likely develop type 2 diabetes within 10 years.

Overweight or obesity. Being overweight or obese raises your risk of heart disease and heart attack. Overweight and obesity also are linked to other heart disease risk factors, such as high blood cholesterol, high blood pressure, and diabetes. Most people who have type 2 diabetes are overweight.

Metabolic syndrome. Metabolic syndrome is the name for a group of risk factors that raises your risk of heart disease and type 2 diabetes. Metabolic syndrome also raises your risk of other health problems, such as stroke.

Lack of physical activity. Lack of physical activity can worsen other risk factors for heart disease, such as unhealthy blood cholesterol levels, high blood pressure, diabetes, and overweight or obesity.

Unhealthy diet. An unhealthy diet can raise your risk of heart disease. Foods that are high in saturated and trans fats, cholesterol, sodium (salt), and sugar can worsen other heart disease risk factors.

Stress. Stress and anxiety can trigger your arteries to tighten. This can raise your blood pressure and your risk of having a heart attack. Stress also may indirectly raise your risk of heart disease if it makes you more likely to smoke or overeat foods high in fat and sugar.

Risk Factors You Can't Control

Age. As you get older, your risk of heart disease and heart attack rises. In men, the risk of heart disease increases after age 45. In women, the risk increases after age 55. In people who have diabetes, the risk of heart disease increases after age 40.

Gender. Before age 55, women seem to have a lower risk of heart disease than men. After age 55, however, the risk of heart disease increases similarly in both women and men.

Family history of early heart disease. Your risk increases if your father or a brother was diagnosed with heart disease before 55 years of age, or if your mother or a sister was diagnosed with heart disease before 65 years of age.

Preeclampsia (pre-e-KLAMP-se-ah). This condition can develop during pregnancy. The two main signs of preeclampsia are a rise in blood pressure and excess protein in the urine. Preeclampsia is linked to an increased lifetime risk of CHD, heart attack, heart failure, and high blood pressure.

Screening and Prevention

Taking action to control risk factors can help prevent or delay heart disease in people who have diabetes and in those who don't. Your risk of heart disease increases with the number of risk factors you have.

One step you can take is to adopt a healthy lifestyle. A healthy lifestyle should be part of a lifelong approach to healthy living. A healthy lifestyle includes:

Some people who have diabetic heart disease (DHD) may have no signs or symptoms of heart disease. This is called “silent” heart disease. Diabetes-related nerve damage that blunts heart pain may explain why symptoms aren't noticed.

Thus, people who have diabetes should have regular medical checkups. Tests may reveal a problem before they're aware of it. Early treatment can reduce or delay related problems.

Some people who have DHD will have some or all of the typical symptoms of heart disease. Be aware of the symptoms described below and seek medical care if you have them.

If you think you're having a heart attack, call 9–1–1 right away for emergency care. Treatment for a heart attack works best when it's given right after symptoms occur.

Coronary Heart Disease

A common symptom of coronary heart disease (CHD) is angina. Angina is chest pain or discomfort that occurs if your heart muscle doesn't get enough oxygen-rich blood.

Angina may feel like pressure or squeezing in your chest. You also may feel it in your shoulders, arms, neck, jaw, or back. Angina pain may even feel like indigestion. The pain tends to get worse with activity and go away with rest. Emotional stress also can trigger the pain.

See your doctor if you think you have angina. He or she may recommend tests to check your coronary arteries and to see whether you have CHD risk factors.

Some people don't realize they have CHD until they have a heart attack. A heart attack occurs if a blood clot forms in a coronary artery and blocks blood flow to part of the heart muscle.

The most common heart attack symptom is chest pain or discomfort. Most heart attacks involve discomfort in the center or left side of the chest that often lasts for more than a few minutes or goes away and comes back.

The discomfort can feel like uncomfortable pressure, squeezing, fullness, or pain. The feeling can be mild or severe. Heart attack pain sometimes feels like indigestion or heartburn. Shortness of breath may occur with or before chest discomfort.

Heart attacks also can cause upper body discomfort in one or both arms, the back, neck, jaw, or upper part of the stomach. Other heart attack symptoms include nausea, vomiting, light-headedness or sudden dizziness, breaking out in a cold sweat, sleep problems, fatigue, and lack of energy.

Some heart attack symptoms are similar to angina symptoms. Angina pain usually lasts for only a few minutes and goes away with rest. Chest pain or discomfort that doesn't go away or changes from its usual pattern (for example, occurs more often or while you're resting) can be a sign of a heart attack.

If you don't know whether your chest pain is angina or a heart attack, call 9–1–1 right away for emergency care.

Not everyone who has a heart attack has typical symptoms. If you've already had a heart attack, your symptoms may not be the same for another one. Also, diabetes-related nerve damage can interfere with pain signals in the body. As a result, some people who have diabetes may have heart attacks without symptoms.

Heart Failure

The most common symptoms of heart failure are shortness of breath or trouble breathing, fatigue, and swelling in the ankles, feet, legs, abdomen, and veins in your neck. As the heart weakens, heart failure symptoms worsen.

People who have heart failure can live longer and more active lives if the condition is diagnosed early and they follow their treatment plans. If you have any form of DHD, talk with your doctor about your risk of heart failure.

Diabetic Cardiomyopathy

Diabetic cardiomyopathy may not cause symptoms in its early stages. Later, you may have weakness, shortness of breath, a severe cough, fatigue, and swelling of the legs and feet.

Diagnosis

Your doctor will diagnose diabetic heart disease (DHD) based on your signs and symptoms, medical and family histories, a physical exam, and the results from tests and procedures.

Doctors and researchers are still trying to find out whether routine testing for DHD will benefit people who have diabetes but no heart disease symptoms.

Blood Pressure Measurement

To measure your blood pressure, your doctor or nurse will use some type of a gauge, a stethoscope (or electronic sensor), and a blood pressure cuff.

Most often, you'll sit or lie down with the cuff around your arm as your doctor or nurse checks your blood pressure. If he or she doesn't tell you what your blood pressure numbers are, you should ask.

Blood Tests

Blood tests check the levels of certain fats, cholesterol, sugar, and proteins in your blood. Abnormal levels of these substances may show that you're at risk for DHD.

A blood test also can check the level of a hormone called BNP (brain natriuretic peptide) in your blood. The heart makes BNP, and the level of BNP rises during heart failure.

Chest X Ray

A chest x ray takes pictures of the organs and structures inside your chest, such as your heart, lungs, and blood vessels. A chest x ray can reveal signs of heart failure.

EKG (Electrocardiogram)

An EKG is a simple, painless test that detects and records your heart's electrical activity. The test shows how fast your heart is beating and its rhythm (steady or irregular). An EKG also records the strength and timing of electrical signals as they pass through your heart.

An EKG can show signs of heart damage due to CHD and signs of a previous or current heart attack.

Stress Test

Some heart problems are easier to diagnose when your heart is working hard and beating fast. Stress testing gives your doctor information about how your heart works during physical stress.

During a stress test, you exercise (walk or run on a treadmill or pedal a bicycle) to make your heart work hard and beat fast. Tests are done on your heart while you exercise. If you can’t exercise, you may be given medicine to raise your heart rate.

Urinalysis

For this test, you'll give a sample of urine for analysis. The sample is checked for abnormal levels of protein or blood cells. In people who have diabetes, protein in the urine is a risk factor for DHD.

Other Tests and Procedures

Your doctor may refer you to a cardiologist if your initial test results suggest that you have a form of DHD. A cardiologist is a doctor who specializes in diagnosing and treating heart diseases and conditions.

The cardiologist may recommend other tests or procedures to get more detailed information about the nature and extent of your DHD.

Reducing or relieving heart disease symptoms, such as angina (chest pain or discomfort)

Preventing or delaying heart disease complications, such as a heart attack

Repairing heart and coronary artery damage

Following the treatment plan your doctor recommends is very important. Compared with people who don't have diabetes, people who have the disease are at higher risk for heart disease, have additional causes of heart disease, may develop heart disease at a younger age, and may have more severe heart disease.

Taking action to manage multiple risk factors helps improve your outlook. The good news is that many lifestyle changes help control multiple risk factors.

Lifestyle Changes

Following a healthy lifestyle is an important part of treating diabetes and DHD. Some people who have diabetes can manage their blood pressure and blood cholesterol levels with lifestyle changes alone.

Following a Healthy Diet

A healthy diet includes a variety of vegetables and fruits. It also includes whole grains, fat-free or low-fat dairy products, and protein foods, such as lean meats, poultry without skin, seafood, processed soy products, nuts, seeds, beans, and peas.

Maintaining a Healthy Weight

Controlling your weight helps you control heart disease risk factors. If you’re overweight or obese, work with your doctor to create a reasonable weight-loss plan.

For more information about losing weight or maintaining your weight, go to the Health Topics Overweight and Obesity article.

Being Physically Active

Regular physical activity can lower many heart disease risk factors, and it helps control your blood sugar level. Physical activity also can improve how insulin works. (Insulin is a hormone that helps turn glucose into energy.)

Generally, adults should do at least 150 minutes (2 hours and 30 minutes) of moderate-intensity physical activity each week. You don’t have to do the activity all at once. You can break it up into shorter periods of at least 10 minutes each.

Talk with your doctor about what types and amounts and physical activity are safe for you. People who have diabetes must be careful to watch their blood sugar levels and avoid injury to their feet during physical activity.

A CRT device is a type of pacemaker. A pacemaker is a small device that helps control abnormal heart rhythms. It’s placed under the skin of the chest or abdomen. A CRT device helps the heart's lower chambers contract at the same time, which may decrease heart failure symptoms.

An ICD is similar to a pacemaker. An ICD is a small device that’s placed under the skin of the chest or abdomen. The device uses electrical pulses or shocks to help control dangerous heart rhythms.

Your doctor also may recommend a pacemaker or ICD to treat diabetic cardiomyopathy. Other types of surgery also are used to treat this type of heart disease.

Diabetes-Specific Treatment Issues

The treatments described above are used for people who have DHD and for people who have heart disease without diabetes. However, some aspects of heart disease treatment differ for people who have diabetes.

Treatment for High Blood Pressure and High Blood Cholesterol

Treatment for high blood pressure and high blood cholesterol often begins earlier in people who have diabetes than in those who don't. People who have diabetes also may have more aggressive treatment goals.

For example, your doctor may prescribe medicines called statins even if your blood cholesterol levels are in the normal range. Your doctor also may prescribe statins if you're older than 40 and have other heart disease risk factors.

Target goals for LDL cholesterol (sometimes called "bad" cholesterol) and high blood pressure also are lower for people who have diabetes than for those who don't. Studies suggest that most people who have diabetes will need more than one blood pressure medicine to reach their goals.

Research also has shown that some people who have diabetes may benefit more from certain blood pressure and cholesterol medicines than from others.

One example is a group of cholesterol medicines called bile acid sequestrants (such as cholestyramine). This type of medicine may offer advantages for people who have type 2 diabetes. It appears to improve blood sugar control and lower LDL cholesterol.

Treatment for Heart Failure

Some studies suggest that certain medicines may have advantages for treating heart failure in people who have diabetes. These medicines include ACE inhibitors, angiotensin receptor blockers, aldosterone antagonists, and beta blockers.

Research shows that two blood sugar medicines (insulin and sulfanylureas) don't seem to reduce the risk of heart failure in people who have type 2 diabetes. A third medicine (metformin) shows promise, but research is still ongoing.

Heart Attack Prevention

Doctors may recommend aspirin for people with diabetes who are at increased risk for heart disease and heart attack. Taken each day, low-dose aspirin may prevent blood clots that can lead to a heart attack.

People with diabetes who are at increased risk include most men older than 50 and most women older than 60 who have one or more of the following risk factors:

Smoking

High blood pressure

High blood cholesterol

A family history of early heart disease

A higher than normal level of protein in their urine

Blood Sugar Control

Controlling blood sugar levels is good for heart health. For example, controlling blood sugar improves everyday heart function for people who have diabetes and heart failure.

Slowing the progress of atherosclerosis (the buildup of plaque in the arteries)

Protecting your heart from heart muscle damage

Lifestyle changes and ongoing care can help you manage DHD.

You also should learn the warning signs of heart problems. People who have diabetes have double the risk of heart attack as the general population.

If you have signs and symptoms of a heart attack, call 9–1–1 right away. For more information, go to the section on warning signs and symptoms below.

Lifestyle Changes

Adopting a healthy lifestyle can help you control DHD risk factors. However, making lifestyle changes can be a challenge.

Try to take things one step at a time. Learn about the benefits of lifestyle changes, and make a plan with specific, realistic goals. Reward yourself for your progress.

The good news is that many lifestyle changes help control multiple risk factors. For example, physical activity lowers your blood pressure, helps control your blood sugar level, reduces stress, and helps control your weight.

Ongoing Care

If you have DHD, having ongoing care is important. Your doctor will track your blood pressure, blood cholesterol and triglyceride levels, and blood sugar level (hemoglobin A1c) with routine tests. These tests will show whether your doctor needs to adjust your treatment.

Your doctor also will want to check other factors that can contribute to your risk of DHD, such as your weight.

Talk with your doctor about how often you should schedule followup visits or blood tests. Between visits, call your doctor if you have any new or worsening symptoms.

Seek the care and support you need from your health care team to manage your DHD. For example:

Check with your doctor before starting any new physical activity.

See a nutritionist or dietitian if you need help learning about or following a healthy diet that helps control your blood sugar level.

Talk with your doctor, nurse, or pharmacist if you're having trouble taking all of your medicines on schedule, or if you're having side effects from your medicines.

Emotional Issues and Support

Living with DHD may cause fear, anxiety, depression, and stress. You may worry about heart problems or making lifestyle changes that are necessary for your health.

Talk about how you feel with your health care team. Talking to a professional counselor also can help. If you’re very depressed, your doctor may recommend medicines or other treatments that can improve your quality of life.

Joining a patient support group may help you adjust to living with DHD. You can see how other people have coped with diabetes and heart disease. Talk with your doctor about local support groups or check with an area medical center.

Support from family and friends also can help relieve stress and anxiety. Let your loved ones know how you feel and what they can do to help you.

Warning Signs and Symptoms

If you think you’re having a heart attack, call 9–1–1 right away. Heart attack treatment works best when it's given right after symptoms occur. The signs and symptoms of a heart attack may include:

Chest pain or discomfort. This involves uncomfortable pressure, squeezing, fullness, or pain in the center of left side of the chest that can be mild or strong. This pain or discomfort often lasts more than a few minutes or goes away and comes back.

Upper body discomfort in one or both arms, the back, neck, jaw, or upper part of the stomach.

Shortness of breath, which may occur with or before chest discomfort.

Nausea (feeling sick to your stomach), vomiting, light-headedness or sudden dizziness, or breaking out in a cold sweat.

Symptoms also may include sleep problems, fatigue (tiredness), and lack of energy. The more signs and symptoms you have, the more likely it is that you're having a heart attack. However, not everyone who has a heart attack has these typical symptoms.

Even if you've already had a heart attack, your symptoms may not be the same for another one. Some people who have diabetes have no symptoms when they have a heart attack. (This is called a "silent" heart attack.) Diabetes-related nerve damage that blunts heart pain may explain why symptoms aren't noticed.

Early treatment can prevent or limit damage to the heart muscle. Don't drive yourself or have friends or family drive you to the hospital. Call an ambulance so that medical personnel can begin life-saving treatment on the way to the emergency room.

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